Reamer Wear Protection Assembly and Method

ABSTRACT

Embodiments of a reamer of the present invention generally include a front end containing components, such as pie wedge-shaped corebuster components, that are substantially axially disposed with respect to the axis of rotation of the reamer, wherein the pie wedges include abrasion-resistant inserts, which may be cylindrical in shape, oriented substantially longitudinally with respect to the axis of rotation of the reamer. Embodiments of a method of using an apparatus of the present invention are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.63/033,481, filed on Jun. 2, 2020, which application is incorporatedherein by reference as if reproduced in full below.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

This invention relates to an apparatus and method for sub-surfaceHorizontal Directional Drilling (HDD). HDD is utilized to create anunderground pathway without excavation. An example of HDD may be foundin U.S. Pat. No. 5,242,026 to Deken, et al., which is incorporatedherein by reference in its entirety. One type of apparatus utilized inHDD is a borehole cutter, also known as a “reamer.” Examples of reamersmay be found in U.S. Pat. No. 6,386,302 to Beaton, and U.S. Pat. No.10,428,586 to Wagner et al., which are incorporated herein by referencein their entirety.

DESCRIPTION OF THE RELATED ART

Within the HDD industry, the underground pathways (bores or holes) areusually not straight and need to be steered to create the necessaryprofile to avoid surface and sub-surface obstacles. Typically, a bore iscreated by first constructing a pilot hole using guidance means and adownhole excavating assembly comprising a pilot bit or small-diameterreamer with a bend in or adjacent thereto to steer the bore in a desireddirection. The excavating assembly is usually powered by anabove-ground, motorized unit (rig) to provide rotational and/ordown-hole force. The pilot hole may then be opened using a largerdiameter tool, such as a reamer, in one or more multiple passes tocreate a progressively larger diameter hole. The reamers can be pushedand/or pulled and do not require steering as they follow the profile ofthe original pilot hole. In order for the larger reamers to follow thepreviously drilled hole, it is necessary for the reamer to becentralized in the hole so that it can cut fresh rock and create a holesubstantially concentric to the original hole.

A typical reamer will comprise several major components, including acollar, cutting elements, front-end, fluid chamber, and supportinggussets. The reamer is designed to concurrently apply load to andfracture the rock, as well as direct drilling fluid, such as mud orwater, to flush the cuttings away and expose fresh rock to be drilled. Areamer may be comprised of tubular steel, with forged, cast and/ormachined components, and steel plates. The reamer components, such asthe main and rear plates, as well as the gussets, are assembled andtypically welded together to complete a single assembly that is able totransfer the rig-supplied load to the rock.

In various embodiments, prior art reamers contain a front end and collarthat are designed to fit into the previously drilled hole in order tocentralize the reamer segments so that the bore can be outwardlyconcentrically expanded in relation to the previously drilled hole. Inone configuration, the front end comprises a plurality of gussets thatforms a circular stabilizing body and is beveled outwardly from thecollar toward the section of the reamer containing the cutting elements,to enable the collar to follow the previously drilled hole. Thefront-end may comprise replaceable, sacrificial components, oftencollectively referred to as a “corebuster,” which are usually disposedcircumferentially about the front-end proximate its maximum diametersection.

A corebuster may comprise an annular component, either in the form of asingular solid component, or the annular component may comprise aplurality of segments (e.g., “pie wedges”) which cooperatively form acontinuous annular structure. Typically, a corebuster comprises one ormore abrasive surfaces designed to contact the rock being drilled. Suchabrasive surfaces may be on the pie wedges and/or sections of thegussets. In one aspect, when the corebuster rotates and is forcedagainst the previously drilled hole, it provides guidance so that thereamer follows the previously drilled hole and simultaneously providesstabilization to the reamer. In operation, rotational friction betweenthe outer surface of the corebuster and the rock being drilled resultsin abrasion of the outer surface of the corebuster. Accordingly,corebusters possess a limited operational lifetime. While corebustersmay be readily replaced, greater drilling efficiency is achieved whenthe corebuster maintains its outer surface integrity as long as possibleduring a drilling operation. To this end, prior art reamers havefrequently employed corebusters which have had an abrasion-resistant(hardmetal) coating applied to the outer surface of the corebuster, orwhich have had abrasion-resistant inserts (e.g., carbides) at leastpartially inserted into the outer surface of the corebuster. In theprior art, such inserts are typically inserted into holes drilledperpendicular to the axis of rotation of the reamer. While thesemodifications often increase useful lifetimes of the corebusters, itwould be desirable to even further increase the robustness of thecorebuster and extend the useful lifetime thereof.

BRIEF SUMMARY OF THE INVENTION

Embodiments of an apparatus of the present invention generally include areamer comprising a corebuster, wherein a plurality of insertscomprising an abrasion-resistant material is disposed at least partiallywithin the outer surface of the corebuster in an orientationsubstantially parallel to the axis of rotation of the reamer.Embodiments of a method of utilizing an apparatus of the presentinvention are also provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a depiction of an embodiment of a prior art reamer.

FIG. 2 is a depiction of an embodiment of a reamer of the presentinvention.

FIG. 3 is another depiction of the embodiment of the reamer of thepresent invention depicted in FIG. 2.

FIG. 4 is a depiction of an embodiment of a front end of the presentinvention.

FIG. 5A is a depiction of an embodiment of a portion of the presentinvention wherein a pie wedge is equipped with a plurality ofabrasion-resistant inserts.

FIG. 5B is a depiction of an embodiment of a portion of the presentinvention wherein a pie wedge is equipped with a plurality ofabrasion-resistant inserts.

FIG. 5C is a depiction of an embodiment of a portion of the presentinvention wherein a pie wedge is equipped with a plurality ofabrasion-resistant inserts.

FIG. 5D is a depiction of an embodiment of a portion of the presentinvention wherein a pie wedge is equipped with a plurality ofabrasion-resistant inserts.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

The exemplary embodiments are best understood by referring to thedrawings with like numerals being used for like and corresponding partsof the various drawings. As used herein, longitudinal refers to the axisA-A identified in FIGS. 1 and 2 (i.e., the axis of rotation of thereamer), and axial refers to a direction perpendicular to axis A-A ofFIGS. 1 and 2. The directions top and bottom as used in thisspecification are used for descriptive purposes only, and otherorientations are contemplated.

Referring to FIG. 1, a prior art reamer 1 is depicted. As shown in FIG.1, reamer 1 comprises an up-hole pipe section 3, up-hole gussets 5,fluid chambers 7, cutting elements 9, front end 11, and a down-hole pipesection (collar) 21. In the reamer depicted in FIG. 1, front end 11comprises front-end gussets 13, longitudinal corebuster components 17,and axial corebuster components (“pie wedges”) 15. Longitudinalcorebuster components 17 and/or pie wedges 15 may comprise a pluralityof wear-resistant inserts 19 embedded in a portion of the exteriorsurface thereof. As would be understood by one skilled in the art,longitudinal corebuster components 17, and pie wedges 15 are subject towear during drilling operations and must be periodically replaced.

Referring now to FIG. 2, an embodiment of a reamer 100 of the presentinvention is depicted. As shown in the embodiment of FIG. 2, reamer 100,like prior art reamer 1, comprises an up-hole pipe section 3, up-holegussets 5, fluid chambers 7, cutting elements 9, front end 11, collar21, with front end 11 comprising front-end gussets 13, longitudinalcorebuster components 17, and axial corebuster components (“pie wedges”)15. In various embodiments of a reamer 100, axial corebuster components15 may comprise a plurality of wear-resistant inserts 119 embeddedlongitudinally (i.e., substantially parallel to the axis of rotation ofthe reamer) into a portion of an exterior surface 25 thereof. In variousembodiments, one or more substantially longitudinally oriented wearresistant inserts 119 comprises a substantially cylindrical component,although the invention is not so limited and other geometries of inserts119 may be employed. In one embodiment, an insert 119 may be greater inlength than in diameter. In one embodiment, an insert 119 comprises asingular component, while in other embodiments (e.g., FIG. 5C, describedbelow), an insert 119 may comprise a plurality of componentscooperatively arranged. FIG. 3 depicts a different view of theembodiment of the reamer 100 depicted in FIG. 2.

In various embodiments, one or more inserts 119 are positioned proximateor penetrating an outer surface 27 of the pie wedge 15 (see FIG. 4) sothat they make can make contact with the pilot hole wall as wear occursto the front-end during the reaming process. In various embodiments,inserts 119 may be retained at least partially within pie wedge 15 byinterference fit, shrink fit, a brazing process (e.g., silver solder),or may be mechanically captivated, although the invention is not solimited and other methods of retainment may be employed, as would beunderstood by one skilled in the art. In other embodiments of thepresent invention (not shown), one or more abrasion-resistant inserts119 may be positioned longitudinally at least partially within anexterior surface 23 of longitudinal corebuster component 17. In varioussuch embodiments, one or more abrasion-resistant inserts 119 may be sopositioned at least partially within a beveled section 24A of exteriorsurface 23 of longitudinal corebuster component 17, and/or within asubstantially non-beveled section 24B of exterior surface 23 oflongitudinal corebuster component 17.

In various embodiments, abrasive inserts 119 may comprise materials suchas, but not limited to, tungsten carbide, tungsten carbide/cobaltalloys, nickel based alloys (e.g., Hastelloy® or Inconel®), cobaltalloys (e.g., Stellite®), cobalt/carbide hardfacing (e.g., applying acobalt & carbide matrix by various welding processes including, but notlimited to, tig, mig, spray & arc), copper alloys (e.g., berylliumcopper), titanium, iron based alloys (e.g., standard, hardened,case-hardened, through-hardened), hardenable stainless steel alloys(e.g., 400 series and 17-4), and natural and polycrystalline diamond(e.g., PCD and PDC).

FIG. 4 depicts an embodiment of a front end of a reamer 100. As shown inthe embodiment of FIG. 4, an insert 119 may be partially exposed fromouter exterior surface 27 of pie wedge 15. In one embodiment, exposureof a portion of an insert 119 from outer exterior surface 27 of piewedge 15 may comprise exposure from a beveled section 31 of outerexterior surface 27. In various embodiments, beveled section 31 of outerexterior surface 27 may be disposed proximate a lower exterior surface29 of a pie wedge 15, or pie wedge 15 lower exterior surface 29 maycomprise beveled section 31 of outer exterior surface 27.

FIGS. 5A, 5B, 5C, and 5D depict various embodiments of the presentinvention wherein a pie wedge 15 is equipped with inserts 119. In theembodiment of FIG. 5A, abrasion-resistant inserts 119 are partiallycontained within outer surface 27 of pie wedge 15, wherein at least aportion of the inserts 119 protrudes axially outwardly from outersurface 27, and wherein at least a portion of the inserts 119 protrudeslongitudinally outwardly from beveled section 31 of outer surface 27.

In the embodiment of FIG. 5B, inserts 119 are partially contained withinouter surface 27 of pie wedge 15, wherein at least a portion of theinserts 119 protrude axially outwardly from outer surface 27, andwherein inserts 119 are disposed in a recessed position with regard tobeveled section 31 of outer exterior surface 27.

In the embodiment of FIG. 5C, inserts 119 each comprise a plurality ofabrasion-resistant insert segments (not individually labeled). Althoughthe insert segments depicted in FIG. 5C are of approximately the samelength and diameter, the invention is not so limited and othergeometries may be employed. In addition, although in FIG. 5C the insertsegments are depicted as abutting each other, the invention is not solimited, and adjacent insert segments may be separated, such as byspacers, or be otherwise non-abutting.

In the embodiment of FIG. 5D, inserts 119 (drawn predominantly inphantom) are disposed substantially completely within pie wedge 15,proximate outer surface 27, wherein a portion of the inserts 119protrudes longitudinally outwardly from beveled section 31 of outersurface 27.

The embodiments depicted in FIGS. 5A-5D disclose various aspectsregarding employment of abrasion-resistant inserts 119; however, theseexamples are merely exemplary and other embodiments, including, but notlimited to, other types of inserts and positioning thereof, may includecombinations of such features of a particular pie wedge 15 or one ormore pie wedges 15 of a front end 11.

Method

In various embodiments, a method of utilizing embodiments of the presentinvention comprises the following steps:

A Reamer Provision Step, comprising providing a reamer, such as a reamer100, wherein one or more abrasion-resistant inserts, such as insert 119,are embedded in an exterior surface, such as exterior surface 27, of oneor more pie wedge components oriented substantially axially to an axisof rotation of the reamer, such as pie wedge component 15, wherein theinserts are oriented substantially longitudinally to the axis ofrotation of the reamer; and

A Reamer Operation Step, comprising introducing the reamer downhole andoperating the reamer to expand the circumference of a hole.

Operation

In operation, an embodiment of a reamer 100 of the present invention isprovided in a pilot hole; thereupon, the reamer 100 may be rotated andpulled back through, and/or pushed through, the pilot hole to enlargethe diameter thereof as may be desired. As corebuster sections 15 and/or17 of the reamer 100 are worn, the front end 11, or sections thereof,such as one or more pie wedges 15 and/or one or more longitudinalcorebuster components 17, may be replaced and operations may then beresumed.

As would be understood by one skilled in the art, during operation ofthe reamer 100 as described herein, wear to the corebuster typicallyinvolves wearing down of pie wedges 15 and/or or longitudinal corebustercomponents 17 through degradation of outer exterior surface 27 of thepie wedges 15 and/or exterior surface 23 of the longitudinal corebustercomponents 17. Thus, provision of abrasion-resistant inserts 119 asdescribed herein allows for resistant wear thereof to occur along thelength of abrasion-resistant inserts 119. Accordingly, the inserts 119,as positioned in various embodiments of the present invention, providefor the provision of contiguous lengths of abrasion-resistant materialcircumferentially about the corebuster during substantially the entiretyof the working life of the pie wedges 15 and/or longitudinal corebustercomponents 17, and therefore the corebuster.

While the present invention has been disclosed and discussed inconnection with the foregoing embodiments, it will be understood thatthe invention is not limited to the embodiments disclosed, but iscapable of numerous rearrangements, modifications, and substitutions ofparts and elements without departing from the spirit and scope of theinvention.

We claim:
 1. A reamer for horizontal directional drilling comprising: afront end comprising one or more components oriented substantiallyaxially to an axis of rotation of said reamer; wherein: at least onesaid axially oriented component is equipped with one or moreabrasion-resistant members that is at least partially embedded in anouter exterior surface thereof, and that is oriented substantiallylongitudinally with respect to said axis of rotation of said reamer. 2.The reamer for horizontal directional drilling of claim 1, wherein atleast one of said one or more front end components comprises a piewedge.
 3. The reamer for horizontal directional drilling of claim 2,wherein an abrasion-resistant member at least partially protrudesthrough an exterior surface of a pie wedge in which it is at leastpartially embedded.
 4. The reamer for horizontal directional drilling ofclaim 1, wherein at least one of said one or more abrasion-resistantmembers comprises a substantially cylindrical component.
 5. The reamerfor horizontal directional drilling of claim 4, wherein said cylindricalcomponent comprises a plurality of components cooperatively arranged. 6.The reamer for horizontal directional drilling of claim 1, wherein atleast a portion of an exterior surface of at least one said one or morefront end components is beveled.
 7. The reamer for horizontaldirectional drilling of claim 6, wherein at least one of said one ormore abrasion-resistant members at least partially protrudes throughsaid beveled exterior surface.
 8. A reamer for horizontal directionaldrilling comprising: a front end comprising one or more componentsoriented substantially longitudinally to an axis of rotation of saidreamer; wherein: at least one said axially oriented component isequipped with one or more abrasion-resistant members that is at leastpartially embedded in an outer exterior surface thereof, and that isoriented substantially longitudinally with respect to said axis ofrotation of said reamer.
 9. The reamer for horizontal directionaldrilling of claim 8, wherein at least one of said one or more front endcomponents comprises a longitudinal corebuster component.
 10. The reamerfor horizontal directional drilling of claim 8, wherein anabrasion-resistant member at least partially protrudes through anexterior surface of a longitudinal corebuster component in which it isat least partially embedded.
 11. The reamer for horizontal directionaldrilling of claim 8, wherein at least one of said one or moreabrasion-resistant members comprises a substantially cylindricalcomponent.
 12. The reamer for horizontal directional drilling of claim11, wherein said cylindrical component comprises a plurality ofcomponents cooperatively arranged.
 13. The reamer for horizontaldirectional drilling of claim 8, wherein at least a portion of anexterior surface of at least one said one or more front end componentsis beveled.
 14. The reamer for horizontal directional drilling of claim8, wherein at least one of said one or more abrasion-resistant membersat least partially protrudes through said beveled exterior surface. 15.A method of using a reamer for horizontal directional drillingcomprising: providing a reamer for horizontal directional drilling,wherein said reamer comprises: a front end comprising one or morecomponents oriented substantially axially to an axis of rotation of saidreamer; wherein: at least one said axially oriented component isequipped with one or more abrasion-resistant members that is at leastpartially embedded in an outer exterior surface thereof, and that isoriented substantially longitudinally with respect to said axis ofrotation of said reamer; and. operating said reamer to enlarge thediameter of a subsurface hole.
 16. The method of using a reamer forhorizontal directional drilling of claim 15, wherein at least one ofsaid one or more front end components comprises a pie wedge.
 17. Themethod of using a reamer for horizontal directional drilling of claim15, wherein an abrasion-resistant member at least partially protrudesthrough an exterior surface of a pie wedge in which it is at leastpartially embedded.
 18. The method of using a reamer for horizontaldirectional drilling of claim 15, wherein at least one of said one ormore abrasion-resistant members comprises a substantially cylindricalcomponent.
 19. The method of using a reamer for horizontal directionaldrilling of claim 18, wherein said cylindrical component comprises aplurality of components cooperatively arranged.
 20. The method of usinga reamer for horizontal directional drilling of claim 15, wherein: atleast a portion of an exterior surface of at least one said one or morefront end components is beveled; and at least one of said one or moreabrasion-resistant members at least partially protrudes through saidbeveled exterior surface.